Viral meningitis

Viral meningitis - Acute

Definition  

CNS infection characterized by fever, headache, and meningeal symptoms with moderate, predominantly lymphocytic cerebrospinal fluid (CSF) pleocytosis and absence of bacterial or fungal pathogens in CSF

 

Medical History  

* Immunodeficiency disorder

* Infectious disease in mother complicating pregnancy, childbirth AND/OR puerperium

 

Findings  

* Nuchal rigidity

* Altered mental status

* Brudzinski's sign

* Bulging fontanelle

* Kernig's sign

* Asthenia

* Dysphagia

* Fever

* Flaccid paralysis

* Headache

* Increased heart rate

* Irritability

* Light intolerance

* Myalgia

* Nausea, vomiting and diarrhea

* Rash - Acute

* Tachypnea

* Throat symptom

* Vesicular eruption

 

Tests  

 

Suspected and known bacterial meningitis  

* Glucose measurement, CSF: A cerebrospinal fluid (CSF) glucose level under 40 mg/dL, or a ratio of CSF-to-blood glucose that is 0.4 or less, is consistent with but does not diagnose bacterial meningitis .

 

Suspected bacterial meningitis  

* Cerebrospinal fluid culture: Bacterial culture of the cerebrospinal fluid is critical in making the diagnosis of bacterial meningitis, identifying the causative organism, and selecting the appropriate antibiotic treatment regimen .

 

Suspected bacterial meningitis  

* CSF gram stain method: Cerebrospinal fluid Gram stain is a useful method for the preliminary diagnosis of bacterial meningitis; however, a negative Gram stain does not rule out the disease .

 

Suspected bacterial meningitis  

* Cerebrospinal fluid examination: Cerebrospinal fluid findings consistent with bacterial meningitis include decreased glucose level, increased protein level and WBC count, and positive Gram stain and culture .

 

Suspected viral meningitis  

* White blood cell count with differential, Cerebrospinal fluid: In viral meningitis, the cerebrospinal fluid WBC count is usually less than 500 cells/mm3, with mononuclear cells predominating .

 

Normal cerebrospinal fluid glucose levels are about two thirds of simultaneously drawn serum glucose levels.  

* Plasma random glucose measurement

 

Suspected hyponatremia  

* Sodium measurement, serum: Hyponatremia is a sodium serum concentration less than 136 mEq/L and severe hyponatremia is a serum sodium concentration of less than 120 mEq/L .

 

Suspected meningitis  

* Blood culture: Blood cultures should be obtained in all cases of suspected bacterial meningitis, and blood specimens should collected before the start of antibiotic therapy unless it delays treatment.

 

Suspected or known viral encephalitis  

* Sodium measurement, serum: Hyponatremia due to comorbid conditions may be observed in a small number of patients with viral encephalitis .

 

The WBC count may be low, normal, or moderately increased. Hemolytic anemia may be present with group A coxsackievirus infections. Thrombocytopenia may be associated with mumps virus and group A coxsackievirus infections.  

* Complete blood count

    

Suspected meningitis  

* CT of head: A head CT prior to lumbar puncture (LP) is recommended if the clinical presentation suggests a mass lesion or another cause of increased intracranial pressure .

 

The chest x-ray findings may be abnormal with pulmonary involvement.  

* Plain chest X-ray

 

Differential Diagnosis  

* Enterovirus meningitis

* West Nile meningitis

* Mumps meningitis

* Herpes simplex meningitis

* HIV infection with aseptic meningitis

* Lymphocytic choriomeningitis

* Herpes zoster with meningitis

* Bacterial meningitis - Acute

* NONSTEROIDAL ANTIINFLAMMATORY DRUGS

* Bacterial meningitis, partially treated

* Subarachnoid hemorrhage

* Meningitis due to other organisms

* Systemic lupus erythematosus encephalitis

* Meningitis in Lyme disease

* Rocky Mountain spotted fever - Acute

* Viral encephalitis - Acute

* Arbovirus encephalitis

* Abscess of brain - Acute

* Hepatic encephalopathy - Acute

* ANTICHOLINERGIC POISONING

* PHENOTHIAZINES

* SALICYLATES

* Malignant meningitis

* Sarcoid meningitis

 

Treatment  

 

Drug Therapy  

 

Acute pain  

 

ACETAMINOPHEN

Adults: 650 to 1,000 mg orally every 4 to 6 hours as needed (maximum 4 g/day)

Pediatrics: 10 to 15 mg/kg orally or rectally every 4 to 6 hours as needed (maximum 5 doses or 4 g/day)

Neonates: 10 to 15 mg/kg orally or rectally every 6 to 8 hours as needed

 

IBUPROFEN

Adults: 200 to 800 mg orally every 6 to 8 hours as needed (maximum 3.2 g/day)

Pediatrics: 5 to 10 mg/kg orally every 6 to 8 hours as needed (maximum, lesser of 40 mg/kg/day or 2.4 g/day)

 

ACETAMINOPHEN/OXYCODONE HYDROCHLORIDE  

Adults: Oxycodone 5 to 20 mg/acetaminophen 325 to 1,000 mg orally every 4 hours as needed (maximum 4 g acetaminophen/day)

Pediatrics: 0.05 to 0.15 mg/kg of the oxycodone ingredient orally every 4 hours as needed

 

ACETAMINOPHEN/CODEINE PHOSPHATE  

Adults: Codeine 15 to 60 mg/acetaminophen 325 to 1,000 mg orally every 4 hours as needed (maximum 360 mg codeine and 4 g acetaminophen/day)

Pediatrics (3-6 years): 5 mL (12 mg codeine/120 mg acetaminophen per 5 mL) orally every 6 to 8 hours as needed

Pediatrics (7-12 years): 10 mL (12 mg codeine/120 mg acetaminophen per 5 mL) orally every 6 to 8 hours as needed

 

Persistent vomiting  

 

PROCHLORPERAZINE  

Adults: 25 mg rectally twice a day OR 5-10 mg IM, may repeat every 3-4 hours (maximum 40 mg/day) OR 2.5-10 mg IV at a rate not to exceed 5 mg/minute (maximum single dose 10 mg; maximum 40 mg/day)

Pediatrics <20 lbs or < 2 years old: not recommended

Pediatrics 20-29 lbs: 2.5 mg rectally once or twice a day (maximum 7.5 mg/day)

Pediatrics 30-39 lbs: 2.5 mg rectally 2 or 3 times a day (maximum 10 mg/day)

Pediatrics 40-49 lbs: 2.5 mg rectally 3 times a day OR 5 mg rectally twice a day (maximum 15 mg/day)

 

ONDANSETRON  

Adults: 4 mg IV every 6 hours

Pediatrics: 0.1 mg/kg IV every 6 hours

 

Herpes simplex meningitis  

 

ACYCLOVIR

Adults: 10 mg/kg IV every 8 hours for 14-21 days

Pediatrics: 20 mg/kg IV every 8 hours for 14-21 days

 

Procedural Therapy  

 

Dehydration  

* Intravenous fluid replacement: Intravenous fluid replacement is indicated for patients with dehydration when oral replacement cannot be accomplished .